The present invention relates to a method for pulverizing a fibrous material such as chaff, pulp and bamboo, or a plastic material.
There are various known pulverizing methods. Among them, the method of the present invention can be classified as a grinding method. With a typical prior art grinding method as shown in FIG. 5, the material to be pulverized is ground in a stone mill having a fixed lower stone 11 and a rotary upper stone 10. But with this method, since it is difficult to pulverize the material at one operation into powder having a particle size of less than 200 mesh, the material has to be repeatedly classified and ground. Further, with this prior art stone mill type grinder, it is known that about half the material is blown off unground the moment it touches the rotating grinder. Thus, such a conventional method is not only inefficient but also costly.